Rubber tire.



- v Patented Dec. l0, I90l. P; W. LITCHFIELD &. F. R. CHAMBERLAIN.

w 4w n w I wliaichrww, FromkR. Cha m lag RUBBER TIRE (Applicstiog filedJan. 5, 1900.) (No Model.)

Tu: uams psrsias 0).. morouma. wuummon. a. c.

v UNITED STATES PATENT OFFICE.-

PAUL W. LITOHFIELD AND FRANK R. CHAMBERLAIN, OF CHELSEA,

MASSACHUSETTS.

RUBBER TIRE.

SPECIFICATION formingpart of Letters Patent 0. 688,319, dated December10, 1901.

Application filed January 6, 1900. Serial No. 412. (No model.)

To all whom it may concern:

(Be it known that we,-PAUL W. LITCHFIELD and FRANK R. CHAMBERLAIN,citizens of the United States, residing at Chelsea, in the county ofSuifolk and State of Massachusetts, (post-office addressl9 vWinnisi mmetstreet, in said city,) have invented a new and useful Rubber Tire, ofwhich the following is a full,

"1 clear, and exact description.

and especially in pneumatic tires, is the lia- A great difficulty metwith in rubber tires,

bility of the separation" from the rubber of the fabricused therewith.WVhen this'occurs, the tirelmust be removed,sent back to the makers, andthe parts revulcanized together. This occasions much loss oftime,-'considerable expense, and, in addition, a'rapid deterioration ofthe tire, owing to the fact that each vul canization injures the rubberand lessens the life thereof. To remedy this defect and also 5 toconstruct a tire embodying certain other advantages is the object ofthis invention, which consists, essentially, in providing a perforatedfabric for the tire.

Referring to the drawings forming part of this specification, Figure 1is a cross-section of a pneumatic tire embodying our invention. Fig. 2is a face View of a section of our perforated fabric. Fig. 3 is a'diagram'illustrating a section of our fabric when subjected to tensilestrain, and Fig. 4 is across-section of a solid-rubber tire.

As shown in Fig. 2, the perforations 2 in our fabric 1 are preferablyrectangular in'outline and extend'in rows crossing each other atrightangles. Thewarp and weft threads 3 and slie parallel with the two setsof rows of said perforations and are hence unbroken throughout theirlength. These perforations may be formed in the fabric by punching themin an unbroken sheet of duck; but this is objectionable on account ofthe expense involved in the operation, but more on account of theextreme difficulty of punching all the perforations along exactly thesame warp and weft threads, and even a slight infringment upon thethreads 3 and 4: severs more or less thereof, and thereby greatlyweakens the fabric, depriving it of the strength required for the tire.Our preferable method of producing the perforations is by weaving thefabric in such a form originally. This insures the continuity of everythread and the consequent full strength thereof, lightens the fabric bythe consequent absence of more than a single series of threads at eachside of each perforation, and is far more economical than the method ofpunching. This perforated fabric is preferably woven in sheets and thencoated with rubber, the latter being made to wholly fill all theperforations thereof. This makes an unbroken sheet, which is cut intostrips of the requisite dimensions for use in the formation of th'etire,the warp and weft threads running diagonally across the strips. In otherwords, the strips are out upon the bias in the customary way. vThe tireis built up with rubber 6 and plies of this fabricin the usual manner;but it will be observed, as indicated in Fig. 2, that after the tire hasbeen formed and vulcanizedthe rubber extends in unbroken connectionsthrough the perforations, uniting the rubber which is located at p theopposite faces of the fabric. Since the film of rubber in theperforations coalesces with the rubber applied to the tire, becomingafter vulcanization absolutely integral therewith, the said rubber inthe perforations become, in effect, what might be termedrivets,inseparably joining the whole tire together. In

fact, a tire thus made cannot be pulled apart layer from layer. We haveeven found it impossible to separate the plies of this fabric from eachother when experimenting with a narrow annulus of one of our tires. I Ifdesired, all the fabric in a tire may be of this perforated kind or onlythe outer layers thereof, the inner ones being of the ordinary duck.

In addition to this great advantage of rendering a tire absolutelycohesive and incapable of having its cover'or outer layer pull off or ofworking off from the rimour tire is made remarkably resilient. Thereason for this is that the rubber located in eachperforation forms anelastic cushion to resist lateral'distortion. When, therefore,the tireis'madeto slightly expand,the fabric is stretched thereby and the warpand weft threads drawn out of perpendicular with each other-that is tosay, the perforations 2 are each made to assume a rhomboid form, thuselongating the rubber therein in one direction and compressing it inanotherr When the distorting strain immoved', the rubber immediatelyrecovers its rectangular shape, and thereby restores the fabric to itsnormal condition. This distortion of the fabric-threads is illustratedin Fig. 3, where the arrow indicates the direction of the expansionalstrain and the consequentelongation of the diagonal parallel therewith.Al-

. though we have described the tensional strain upon the fabric as beingresisted by said rubber cushions when said perforations extend parallelwith the threads composing the fabric, yet we have found that the sameresult is produced even when the holes are punched irrespective of thewarp and Weft threads. The reason for this we find to be that when thefabric is coated with rubber before being cut into strips suitable forapplication upon a tire all the warp and weft threads thereof arecemented" together, each thread to its neighbonand consequently whenaseries of perforationsare-punched through the fabric without anyattention to locating such perforations-exactly parallel withcertainthreads that those threads which are thereby severed, andconsequently donot'extend unb'rokentlie' entirewid'th of the fabric, do not pull: outfrom the fabric or in any way weaken the same- Hence'we find the fabricto be equally 1 capable of resisting strain and elastically recoveringtherefrom when the holes are punched through the fabric as when woventherein and so insured to be parallel with the threads;

fectof the rubber rivets in the perforations to be equally perfect'whenthe perforations We further find the cushioning ef- 1 are of othercontours than the square shape shown.

While Fig. 1 shows our fabric utilized in the construction of apneumatic tire, Fig. 4 shows the fabric as applied to a solid-rubbertire, 6 indicating the rubber, and 7 the Wheelrim.

What we claim as our invention, and for which we desire Letters Patent;is as follows; to wit:

1. A tire composed of rubber and fabric; said fabric being tightly wovenbut having rows of perforations therein extending par allel to the warpand weft threads thereof, whereby not only are the plies of fabricsecurely bound together-by the bodies of rubber extending through saidperforations, but said bodies of rubber serve as cushions to elasticallyresist tensional strain on said fabric' in directions oblique to thethreads thereof, substantially as set forth.

2. A tire composed of rubber and fabric,

' said fabrichaving its warp and weft threads separated into sets, suchsets being separated one from the other and therebyca'used to form therectangular blank spaces or perforations extending in rows parallel withsaid threads, substantially as set forth;

In testimony that-we claim. the foregoing invention we have hereunto setour hands this' lst day of January, 1900.

PAUL W. LITC-HFI'ELD'. FRANK R. CHAMBERLAIN. \Vit'nesses:

A. B. UPHAM, GUY H. HOLLIDAY.

